<template>
  <div>
    <el-upload
      :action="action"
      list-type="picture"
      :multiple="false"
      :show-file-list="showFileList"
      :file-list="fileList"
      :before-upload="beforeUpload"
      :on-remove="handleRemove"
      :on-success="handleUploadSuccess"
      :on-preview="handlePreview"
    >
      <el-button size="small" type="primary">点击上传</el-button>
      <div slot="tip" class="el-upload__tip">只能上传jpg/png文件，且不超过10MB</div>
    </el-upload>
    <el-dialog :visible.sync="dialogVisible">
      <img width="100%" :src="fileList[0].url" alt="">
    </el-dialog>
  </div>
</template>

<script>
export default {
  name: 'SingleUpload',
  props: {
    value: {
      type: String,
      default: null
    }
  },
  data() {
    return {
      action: process.env.VUE_APP_BASE_API + '/system/attachment/upload',
      dialogVisible: false
    }
  },
  computed: {
    imageUrl() {
      return this.value
    },
    imageName() {
      if (this.value != null && this.value !== '') {
        return this.value.substr(this.value.lastIndexOf('/') + 1)
      } else {
        return null
      }
    },
    fileList() {
      return [{
        name: this.imageName,
        url: this.imageUrl
      }]
    },
    showFileList: {
      get: function() {
        return this.value !== null && this.value !== '' && this.value !== undefined
      },
      set: function(newValue) {
      }
    }
  },
  methods: {
    emitInput(val) {
      this.$emit('input', val)
    },
    handleRemove(file, fileList) {
      this.emitInput('')
    },
    handlePreview(file) {
      this.dialogVisible = true
    },
    beforeUpload(file) {
      return new Promise((resolve, reject) => {
        resolve(true)
      })
    },
    handleUploadSuccess(res, file) {
      this.showFileList = true
      if (res.code === 200) {
        this.fileList.pop()
        this.fileList.push({ name: file.name, url: process.env.VUE_APP_ATTACHMENT_URL + '/' + res.data[0].fileUrl })
        this.emitInput(this.fileList[0].url)
      }
    }
  }
}
</script>
<style>

</style>
